Hydraulic mechanism



Feb. 11, 1969 w MARSH 3,426,694 I HYDRAULIC MECHANISM Filed March 25, 1966 Sheet of 6 IO 2|2 1 l INVENTOR WALTER H. MARSH JMWMWM 77W #06 A'ITO ENEYS 1959 w. H. MARSH HYDRAULIC MECHANISM Filed March 25, 1966 Sheet 2 V11! X alll II 'WNY I60 2*" I42 I42 j so INVENTOR Wm, TER h. MARSH MW via/QM w wofim Feb. 11, 1969 w MARSH 3,426,694

HYDRAULIC MECHANISM Filed March 25, 1966 Sheet 3 of e INVENT OR WAL 759 /-I. MARSH Feb. 11, 1969 w. H. MARSH HYDRAULIC MECHANISM Sheet Filed March 25, 1966 I with v HW L INVENTOR WALTER H. MARSH BY 7m 77% I 77% wi m Feb. 11, 1969 Filed March 25. 1966 W. H. MARSH HYDRAULIC MECHANISM Sheet 5 of 6 INVENTOR WALTER h. MARS/v z 1 f I A ORNEY5' Feb. 11, 1969 w. H. MARSH HYDRAULIC MECHANISM Shet 6 of6 Filed March 25, 1966 INVENT OR WAL 75/? h. MARSH I f ATTO BY;

United States Patent 3,426,694 HYDRAULIC MECHANISM Walter H. Marsh, Pittsburgh, Pa, assiguor to Rockwell Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Mar. 25, 1966, Ser. No. 537,393

US. Cl. 103-125 Claims Int. Cl. F04c 1/16, 17/02; Ftllc 11/00 ABSTRACT OF THE DISCLOSURE tering through either opening is divided, and the divided streams are so directed in opposite directions through passages in the rotors that the axially directed fluid forces acting on the rotors and, consequently, on the rotorymounting shaft are substantially balanced.

The present invention relates to hydraulic mechanisms and more particularly to a rotary hydraulic mechanism adapted for use as a pump or motor.

In conventional hydraulic pump or motor units, such as that described in United States Letters Patent No. 2,913,990 issued on Nov. 24, 1959 to Charles R. Taylor for a Hydraulic Mechanism, fluid flowing through the pump or motor housing objectionably exerts unbalanced axial forces on the energy-transferring rotor and shaft assembly. The unbalanced axial loading of the rotor assembly requires the use of thrust bearings or plates and results in undue wear of the shaft bearing members. Another shortcoming of conventional hydraulic mechanisms of the type described in the aforesaid Patent No. 2,913,- 990 is that the unit, irrespective of fluid chamber size, has a limited capacity which is, to a great extent, determined by the rate at which fluid can flow into and out of the alternately contracting and expanding working chambers under normally encountered fluid pressure conditions.

The present invention contemplates and has as its major object the provision of a novel hydraulic rotor unit which uniquely balances the hydraulic loading of the rotor and shaft assembly in addition to increasing the capacity of the unit over conventional mechanisms having working chamber volumes of comparable size.

In fulfilling the foregoing object, this invention provides for a dual rotor assembly having a pair of axially aligned rotors through which fluid is directed in axially opposite directions. In this manner, the axially directed fluid pressures acting on the rotors are balanced to eliminate the need for rotor shaft thrust bearings or plates and to minimize the bearing loads, As a result, the bearing construction may be simplified and undue Wear of the rotor shaft support bearings is avoided.

By employing dual rotors in accordance with this invention, two fluid working chambers are provided for in comparison with a single fluid working chamber as in the conventional hydraulic mechanism described in the aforesaid patent No. 2,913,990. Since two fluid working chambers are provided in the mechanism of this invention, the size of each chamber need not be larger than one-half the size of the single chamber in the mechanism of the aforesaid patent for obtaining the same capacity. The smaller size of the chambers in the mechanism of this invention thus assures that the chambers will be completely filled with fluid to increase the mass of fluid handled by the mechanism, thereby improving its efficiency.

Accordingly, a more specific object of this invention is to provide for a novel dual rotor hydraulic mechanism wherein a plurality of fluid working chambers are provided for and wherein fluid flowing through the inlet of the mechanism is divided to flow in axially opposite directions through the rotor elements of the dual rotor assembly.

Still a further object of this invention is to provide a novel dual rotor hydraulic mechanism having a pair of vaned rotors which are angularly offset relative to each other to stagger the intake and discharge of fluid with respect to rotor chambers. This feature of the present invention minimizes pulsations in the discharging fluid and more uniformly distributes the radial loads applied to the rotor and shaft assembly.

Further objects of this invention will appear as the description proceeds in connection with the appended claims and the annexed drawings wherein:

FIGURE 1 is a longitudinal section of a hydraulic mechanism incorporating this invention;

FIGURES 2, 3, 4, and 5 are section respectively taken substantially along lines 22, 3-3, 44, and 55 of FIGURE 1;

FIGURE 6 is a perspective view of the left-hand rotor shown in FIGURE 1;

FIGURE 7 is a left-hand side elevation of the rotor shown in FIGURE 6; and

FIGURES 8 and 9 are right and left-hand side elevations of the right-hand rotor shown in FIGURE 1.

Referring now to the drawings and more particularly to FIGURE 1, the reference numeral 20 generally designates a hydraulic mechanism incorporating the principles of this invention and comprising an open-ended housing 22 of generally cylindrical form. A pair of flanged, diametrically opposed bosses 24 and 26 extend from housing 22 along a common axis normally intersecting the longitudinal housing axis. Bosses 24 and 26 respectively provide a high pressure fluid flow port 28 and a low pressure fluid flow port 31 Housing 22 is formed with a cylindrically smoothwalled through bore 31 which terminates at opposite end in axially directed, machined, mounting flanges 32 and 34. A pair of front and rear bearing holders 36 and 38 are secured by cap screws 40 to the faces of flanges 32 and 34 respectively. Each of the bearing holders 36 and 38 comprises an annular plate having an annular lip 42 which is coaxially received with a pilot fit in bore 31.

Still referring to FIGURE 1, bearing holders 36 and 38 are respectively formed with axially oppositely facing machined flanges 44 and 46. Seal covers 48 and 50 are respectively secured by cap screws 52 to the faces of flanges 44 and 46. Cover 48 is provided with an annular lip 54 which is coaxially received with a piloting fit in a smooth-walled bore 56 formed through bearing holder 36. Similarly, cover 50 has an annular lip 58 coaxially received with a piloting fit in a cylindrically smooth-walled bore 60 formed through bearing holder 38. Bores 56 and 60 axially align with bore 31.

A groove-seated resilient O-ring 62 carried by cover 48 is compressed against the face of flange 44 to provide an annular, fluid-tight seal at the interface between cover 48 and bearing holder 36.

Cover 50 also carries a resilient O-ring 68 which is compressed against the face of flange 46 to provide an annular fluid-tight seal therewith.

A resilient groove-seated O-ring 64 provides an annular fluid-tight seal at the interface between bearing holder 36 and the face of flange 32 on housing 22. Similarly, a resilient, groove-seated O-ring 66 provides a fluidtight seal betwen the interface of bearing holder 38 and flange 34.

With continuing reference to FIGURE 1, an energy transfer shaft 70 is shown to extend coaxially through housing 22, bores 56 and 60, and axially aligned bores 72 and 74 formed through the end walls of covers 48 and 50 respectively. Shaft 70 is journalled for rotation by antifriction bearing assemblies 76 and 78. The outer races of assemblies 76 and 78 are respectively received with pressed fits in bores 56 and 60.

Still referring to FIGURE 1, a shaft seal and bearing retaining assembly 80 is coaxially mounted on the section of shaft 70 in cover 48. Assembly 80 is of suitable construction to provide a fluid-tight seal between cover 48 and the periphery of shaft 70. The inner race of bearing assembly 76 is axially confined between an annular shoulder 82 formed integral with shaft 70 and a bearing lock nut 84 forming a part of assembly 80. Lock nut 84 is threaded onto an intermediate section of shaft 70 axially adjacent to bearing assembly 76. The outer race of bearing assembly 76 is axially confined between lip 54 and an annular bearing retainer 85. Retainer 85 is fixed to bearing holder 36 by cap screws 85a.

A shaft seal and bearing retainer assembly 86 mounted on the opposite end of shaft 70 extending through cover 50 is of the same construction as assembly 80. The bearing lock nut of assembly 86 is indicated at 88 and is threaded onto shaft 70 axially adjacent to bearing assembly 78. Assembly 86 provides a fluid-tight seal between the periphery of shaft 70 and cover 50. The outer race of bearing assembly 78 is axially confined between lock nut 88 and a sleeve 90 which is mounted on shaft 70.

In accordance with this invention, a dual rotor assembly 90 received within housing 22 comprises a pair of vaned rotors 92 and 94. Rotors 92 and 94 are mounted in axially spaced apart relation on shaft 70 and are equidistantly spaced on opposite sides of the diametrical axis which is common to ports 28 and 30. Groove-seated keys 96 and 98 (see FIGURES 2 and 4) respectively nonrotatably fix rotors 92 and 94 to shaft 70.

As shown in FIGURES 2 and 3, rotor 92 is integrally formed with a cylindrical hub section 100 and a pair of diametrically opposed vanes 102 and 104 extending radially from hub section 100. Hub section 100 coaxially receives shaft 70 and is provided with a longitudinally extending, inwardly opening groove in which key 96 is seated.

Rotor 94, as best shown in FIGURES 4 and 5, is the mirror image of rotor 92. Accordingly, like reference numerals suffixed by the letter a have been used to identify the parts of rotor 94. As shown, hub section 100a receives shaft 70 and is formed with a longitudinally extending, inwardly opening groove in which key 98 is seated.

Referring back to FIGURE 1, rotor 92 is axially confined between a pair of sleeves 110 and 112 which are coaxially mounted on shaft 70. Rotor 94 is axially confined between sleeve 110 and an annular shoulder 114 defined by an integral, radially stepped section of shaft 70. Sleeve 110 extends axially between rotors 92 and 94 and butts at opposite ends against hub sections 100 and 100a. Sleeve 112 is axially confined between hub section 100 and a gear 116 non-rotatably mounted on shaft 70. Gear 116 forms a part of a drive train for an abutment vane assembly 118 which will be described in detail later on. Gear 116 is axially confined between sleeves 90 and 112.

As shown in FIGURES 1-5, a vane housing cover assembly 130 comprising a pair of axially spaced apart vane housings 131 and 132 and a vane housing spacer 133 is coaxially received in bore 31 and is confined between the opposed ends of lips 42 on bearing holders 36 and 38. Vane housings 131 and 132 and spacer 133 are axially aligned in bore 31 and are rigidly secured together as a unit by machine screws indicated at 136. Spacer 133 is axially clamped between vane housings 131 and 132 to maintain housings 131 and 132 in abutment with the lips 42 on bearing holders 36 and 38 respectively. The external periphery defined by the assembly of vane housings 131 and 132 and spacer 133 is cylindrically smooth and uniformly diametered to interfit within bore 31. Housings 131 and 132 are respectively formed with uniformly diametered, cylindrically smooth-walled bore sections 138 and 139 at their ends adjacent to spacer 133. Bore sections 138 and 139 are coaxial with bore 31 and respectively, coaxially receive rotors 92 and 94. The ends of the vanes on rotors 92 and 94 are curved to interfit in bore sections 138 and 139 with a close running fit to minimize fluid leakage around the rotor vanes and at the same time to permit the free rotation of the rotors.

As shown in FIGURES 2 and 3, vane housing 131 is formed with four equiangularly spaced apart cylindrical recesses 142 which open radially inwardly into bore section 138. Vane housing 132, as shown in FIGURE 4, similarly is formed with four equiangularly spaced apart cylindrical recesses 144 which open radially into bore section 139 and which axially align with recesses 142. Recesses 142 and 144 have uniformly diametered, segmental circular cross sections, the circumferential extent of which slightly exceeds 180 degrees. Spacer 133 is formed with four equiangularly spaced apart through bores 146 (one shown in FIGURE 1) which align with the longitudinal axes of recesses 142 and 144.

Assembly 118 comprises a series of four rotary abutment vanes 150, 151, 152 and 153, each of which is received in aligning pairs of recesses 142 and 144. Vanes -153 each are formed with uniformly diametered cylindrical sections 156 (see FIGURE 1) which coaxially extend through bores 146 and which are journalled therein by sleeve bearings 158.

As shown in FIGURE 1, vanes 150-153 each are formed with cylindrical end sections 160 which are disposed axially rearwardly of rotor 92. End sections 160 are journalled in sleeve bearings 161 which are coaxially received in cylindrically smooth bores 162. formed in vane housing 131. Vanes 150-153 each have intermediate sections 164 which integrally join sections 156 and 160 and which are received in recesses 142 in radial alignment with rotor 92. Circumferentially between each adjacently disposed pair of vanes 150-153, housing 131 and spacer 133 cooperate to define an inwardly opening recess 165 (see FIGURE 1) which is delimited by the wall of bore section 138 and which receives rotor 92 with a close running fit.

As shown in FIGURES 2 and 3, the sections 164 of vanes 150-153 are cut away to form recesses or pockets 166 each having an arcuate bottom surface. The remaining peripheries of sections 164 are uniform in diameter and cylindrically smooth. Pockets 166 are sufficiently deep to provide a radial clearance between their bottom surfaces and the outer ends of rotor vanes 102 and 104.

Still referring to FIGURE 1, the forward ends of vanes 150-153 each are formed with uniformly diametered cylindrical sections 170 which are journalled in sleeve bearings 172. Sleeve bearings 172 are coaxially received in equiangularly spaced apart bores formed in the forward end of vane housing 132 axially beyond rotor 94. Sections 170 are integrally joined to sections 156 by intermediate sections 176 which are received in recesses 144 in radial alignment with rotor 94. Circumferentially between each adjacent pair of sections 176 housing 132 cooperates with spacer 133 to define an inwardly opening recess 177 (see FIGURE 1) which is delimited by the wall of bore 139 and which receives rotor 94 with a close running fit.

Sections 1'76, as best shown in FIGURES 4 and 5, are each cut away to form recesses or pockets 178. Each of the pockets 178 is formed with an arcuate bottom surface and is of suflicient depth to provide a clearance space between the ends of rotor vanes 102a and 104a. The remaining periphery of each section 176 is cylindrical and uniformly diametered to interfit in its associated recess 144.

In each of the vanes 150153, pockets 166 are angularly offset by 45 degrees with respect to pockets 178 to accommodate rotors 92 and 94 which are offset from each other by an angle of 45 degrees. The purpose of angularly offsetting rotors 92 and 94 will be explained later on.

As shown in FIGURE 1, gear 116 constantly meshes with equiangularly spaced apart pinion gears 180 which are respectively formed rigid with vanes 150-153. Vanes 150-153 thus rotate in timed relation with rotors 92 and 94 whereby pockets 166 and 168 provide for the continuous, unblocked rotation of rotors 92 and 94 respectively.

When the dual rotor hydraulic unit of this invention is operated as a pump, port 30 is connected to a suitable source of fluid, port 28 is connected to a discharge conduit, and shaft 70 is connected to a suitable source of power for rotating rotors 92 and 94 in a counterclockwise direction as viewed from FIGURES 2 and 5. Fluid entering the hydraulic unit through port 30 is medially divided to flow in essentially opposite directions through passages indicated at 184 and 186 in FIG- URE 1. Passages 184 and 186 respectively extend through vane housings 131 and 132 and terminate adjacent to the axially oppositely facing sides of rotors 92 and 94 respectively.

The inner end of passage 184 is in fluid communication with a pair of arcuate, diametrically opposed, ports 188 and 190 (see FIGURES 3 and 6) formed in rotor hub 100 and facing axially toward the rearward end of shaft 70. As best shown in FIGURE 6, an angulated passage 192 formed through hub -0 and rotor vane 102 connects port 188 to a port 194. Port 194 is formed in the side face of rotor vane 102 and opens circumferentially into the bore space between vanes 102 and 104.

As shown in FIGURES 6- and 7, a second angulated passage 196 formed through hub 100* and rotor vane 104 connects port 190 with another side port 198. Port 198 is formed in the side of rotor vane 104 which faces circumferentially in the opposite direction from the rotor vane side face containing port 194. Passages 192 and 196, as best shown in FIGURE 6, extend essentially opposite directions and diagonally with respect to vanes 102 and 104. The stream of fluid flowing through passage 184 is thus divided, passing simultaneously through passages 192 and 196 for entry into the rotor working space in a manner to be described in greater detail later on.

To discharge fluid in the rotor working space defined by bore section 138, a pair of ports 200 and 202 (see FIGURES 6 and 7) are respectively formed in the circum'ferentially oppositely facing sides of rotor vanes 102 and 104. A diagonal passage 206 formed through rotor vane 1-02 and hub 100 connects port 200 to an arcuate port 208 (see FIGURE 2) which is formed in hub 100. A similar diagonal passage 209 (FIGURE 2.) formed through rotor vane 104 and hub 100 connects port 202 to an arcuate port 210 (FIGURE 2). Port 210 is formed in hub 100 diametrically opposite from port 208.

Rotor 94 being the mirror image construction of rotor 92, is formed with the same passages and ports as just described for rotor 92. Accordingly, like reference numerals suflixed by the letter a have been used to designate the corresponding ports and passages in rotor 94 as shown in FIGURES 4, 5, 8 and 9. Ports 208a and 210a face rotor 92, and ports 188a and 190a face in the opposite direction toward the forward end of shaft 70.

Ports 208, 210, 20851, and 210a open into an annular chamber 212 (see FIGURE 1) peripherally surround- 6 ing sleeve between rotors 92 and 94. Chamber 212 is connected to port 28 through circumferential passages formed in housing 22. and indicated at 214 in FIGURE 1.

When the dual rotor hydraulic unit of this invention is operated as a pump, the fluid entering through port 30, as previously mentioned, is divided into two streams which flow generally in opposite directions through passages 184 and 186. The fluid transmitted through passage 184 is turned to flow axially through ports 188 and 190 in rotor 92. Concomitantly, the fluid advancing through passage 186 is turned to flow in an axially opposed direction through ports 188a and 190:! of rotor 94.

In the position of rotor 92 shown in FIGURE 2, the fluid entering port 188 flows through passage 192 and into the bore space circumferentially between rotor vane 102 and vane 151. At this stage, vane 151 is turned toblock flow of fluid into the circumferential space between vane 151 and rotor vane 104. Vane is turned to a position where its pocket 166 faces inwardly, allowing passage of rotor vane 102. At the same time fluid is flowing through passage 192, and fluid entering port flows through passage 196 and into the expanding chamber space circumferentially between rotor vane 104 and abutment vane 153.

As rotor vane 102 advances in a counterclockwise direction beyond abutment vane 150, the latter assumes a position to prevent escape of the fluid between it and abutment vane 151. Fluid from port 18 8 now begins to enter the expanding chamber space between rotor vane 102 and abutment vane 150. Concomitantly, rotor vane 104 advances beyond vane 152 and fluid from port 190 begins to flow into the expanding chamber space between rotor vane 104 and vane 151. In this manner, fluid entering rotor 92 through ports 188 and 190 fills the diametrically opposed chamber spaces between vanes 150453 as these spaces are expanded by the counterclockwise advancement of rotor 92. The chamber space ahead of each of the rotor vanes 102 and 104 thus will be filled with incoming fluid.

When rotor 92 advances beyond the position shown in FIGURE 2, therefore, vane 102 contracts the chamber space ahead of it to compress the low pressure fluid therein and to cause it to flow through port 200 and passage 206 and into chamber 212. At the same time, fluid in the contracting chamber space between rotor vane 104 and abutment vane 151 is compressed and flows through port 202.

Operation of rotor 94 in cooperation with abutment vanes 150153 is the same as that just described for rotor 92.

The compressed fluid entering chamber 212 from ports 208, 210, 208a, and 210a flows through passages 214 and is discharged through port 28.

It will be appreciated that the dual rotor hydraulic unit of this invention will also function as a motor by connecting port 28 to a high pressure fluid source and by connecting port 30 to an exhaust. The high pressure fluid entering port 28 flows into chamber 212. In chamber 212, it divides to flow in axially opposite directions through ports 208 and 210 in rotor 92 and through ports 208a and 210a in rotor 94.

In rotor 92, the high pressure fluid flows through passages 206 and 209 and is discharged through ports 200 and 202 to urge rotor 92 in a clockwise direction as viewed from FIGURE 2. In the position of rotor 92 shown in FIGURE 2, high pressure fluid has entered and expanded in the chamber space between rotor vane 102 and abutment vane 153. Continued clockwise advancement of rotor 92 past abutment vane 150 then provides for the entry of high pressure fluid into the chamber space between rotor vane 102 and abutment vane 150. Thus, as each rotor vane passes one of the abutment vanes 150-153, the chamber space fills with high pressure fluid and expands. In the posit-ion of part shown in FIGURE 2, therefore, the chamber space between rotor vane 102 and abutment vane 151 and between rotor vane 104 and abutment vane 153 will be filled with expanded fluid preparatory to discharge.

As rotor 92 continues to rotate in a clockwise direction, the fluid in the chamber space between vanes 102 and 151 enters port 194 and flows through passage 192 into passage 184. Similarly the fluidin the chamber space between vanes 104 and 153 enters port 198 and flows through passage 196 to passage 184. In this manner, the chamber spaces ahead of the rotor vanes are contracting to discharge fluid while the chamber spaces behind the rotor vanes are being expanded by high pressure fluid. Operation of rotor 94 is the same.

When the hydraulic unit is used as a motor, shaft 70 may be connected to a power consuming device to perform useful work.

From the foregoing, it is clear that when the hydraulic unit is used as a motor, high pressure fluid in chamber 212 flows in axially opposite directions into rotors 92 and 94 and that the expanded fluid leaves rotors 92 and 94 in axially opposite directions. When the hydraulic unit is used as a pump, lOW pressure fluid enters rotors 92 and 94 in axially opposed directions and leaves rotors 92 and 94 in axially opposed directions. As a result, a dynamic axial balance is achieved to substantially eliminate axial bearing loads owing to the pressure of fluid flowing through the mechanism.

The angular offset between rotors 92 and 94 staggers the intake and discharge of fluid with respect to the rotors. This minimizes pulsations in the discharging fluid and more uniformly distributes the radial loads applied to the dual rotor and shaft assembly.

By employing two rotors, the hydraulic unit of this invention will have a greater capacity as compared with a conventional hydraulic unit having a single rotor and a rotor working space equal in volume to the two working spaces around rotors 92 and 94. This is the result of reducing the size of each rotor chamber working space to assure that each working space will be completely filled with fluid. When a single rotor working space of twice the volume of each of the Working spaces around rotors 92 and 94 is used as in conventional units, it may not be completely filled to capacity in the limited time which is provided for the intake cycle. Thus, the dual rotor mechanism of this invention makes more eflicient use of the power input.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

l. A rotary hydraulic mechanism comprising a housing having fluid inlet and outlet openings, a pair of axially aligned, energy transferring rotors mounted in said housing for unitary rotation, means cooperating with each of said rotors as the rotors are rotated for defining alternately expanding and contracting fluid working chambers to effect a transfer of energy relative to fluid introduced into said chambers, passage means formed in said housing and internally through said rotors for connecting said inlet and outlet openings to said chambers when they are respectively expanding and contracting to enable fluid to flow through said housing from inlet openings to said outlet opening, the fluid flowing through said housing being so directed by said passage means that the axially directed fluid force components acting on said rotors are substantially equal and opposite.

2. The rotary hydraulic mechanism defined in claim 1 wherein fluid is directed by first portions of said passage means to flow from said inlet opening, axially in opposite direction into said rotors, and through said rotors to said chambers when expanding, the fluid in said chambers when contracting being further directed by second portions of said passage means to flow back through said rotors, and to leave said rotors in axially opposite directions for flow to said outlet opening.

3. The rotary hydraulic mechanism defined in claim 1 wherein said means providing said chambers comprises vanes on said rotors, the vanes on one of said rotors being angularly offset relative to the vanes on the other of said rotors by a predetermined angle for enabling the expansion and contraction of the chambers at one rotor to lag the expansion and contraction of the chambers at the other of said rotors.

4. The rotary hydraulic mechanism defined in claim 1 wherein said rotors are essentially of identical construction and are disposed in mirror image relation to each other.

5. The rotary hydraulic mechanism defined in claim 1 'wherein said passage means comprises a housing flow channel connected to one of said openings and extending to a region axially between said rotors, first passages in said rotors opening into said channel at axially opposed faces of said rotors, second passages formed through said rotors and opening at axially oppositely facing sides of said rotors, and divided channel means establishing fluid communication between the other of said openings and said second passages where they open at oppositely facing sides of said rotors, said means providing for expansion and contraction of said chambers being operative to cyclically connect said first and second passages to said chambers.

6. The rotary hydraulic mechanism defined in claim 1 comprising a shaft mounting said rotors and being journalled at opposite ends in said housing.

7. The rotary hydraulic mechanism defined in claim 6 wherein said means providing said chambers comprises a plurality of circumferentially spaced apart vanes on each rotor and being movable therewith through an annular working space delimited by each rotor and internal wall surface on said housing, a plurality of rotor abutment members common to both of said rotors and being journalled for rotation in said housing about axes extending substantially parallel to the rotor rotational axes, and drive means connecting said shaft to said rotor abutment members for cyclically moving said members into each working space in close clearance relation with said rotors and out of each working space to permit passage of said vanes.

8. The rotary hydraulic mechanism defined in claim 7 wherein the vanes on each rotor are on diametrically opposite sides of the rotor periphery, the vanes of one rotor being angularly offset relative to the vanes on the other of said rotors to enable the expansion and contraction of the chambers at one rotor to lag the expansion and contraction of the chambers at the other rotor.

9. A rotary hydraulic mechanism capable of operating as pump or a motor and comprising a housing having fluid inlet and outlet openings, a dual rotor assembly journalled for rotation in said housing and having a pair of separately formed vaned rotor elements, means cooperating with said rotor elements and said housing for defining alternately expanding and contracting chambers to effect a transfer of energy relative to fluid admitted to said chambers, and means including passages formed internally through said rotor elements for connecting the expanding chambers to said inlet opening and the contracting chambers to said outlet opening to cause fluid to flow substantially continuously through said outlet opening whenever fluid flows continuously through said inlet open- 10. A rotary hydraulic mechanism capable of operating as either a pump or a rotor and comprising a housing having relatively high and lOW fluid pressure openings, a pair of energy transferring, vaned rotors mounted in said housing for rotation about a common axis, means cooperating with each of said rotors during rotation thereof for defining alternately expanding and contracting fluid working chambers to eflFcct a transfer of energy relative to fluid introduced into the chambers, and means connecting said chambers when expanding to one of said openings and when contracting to the other of said openings to enable fluid to flow through said housing from either one of the openings to the other, said last-mentioned means comprising first passage rneans formed internally through one of said rotors and communicating with associated ones of said chambers, second passage means formed internally through the other of said rotors and communicating with associated ones of said chambers, and means for dividing fluid entering said housing through either of said openings into a plurality of fluid streams and for 1 directing the divided fluid streams to respectively enter said first and second passage means in directions that are axial and opposite relative to said common axis.

References Cited UNITED STATES PATENTS 1,946,097 2/1934 Morris et a1 103125 683,619 10/1901 Osborne 91-81XR 697,075 4/1902 Dow 9181 XR 1,766,519 6/1930 Johnson 9190 2,292,987 8/1942 Berry 91-90 XR 2,905,095 9/1959 Hartmann et a1 103125 2,917,898 12/1959 Berry 91-82 DONLEY J. STOCKING, Primary Examiner. T. R. HAMPSHlRE, Assistant Examiner.

US. Cl. X.R. 

